I order the single strings in bulk 11,14,22,30,40,52 stanard bronze strings from juststrings.com

These work really well for my two Martin 00-18 acoustic electrics. I use the LRBaggs bridge saddle pickup with the LRBaggs para-pro floor preamp that has a built in direct out. These strings have a great feel and last. I play them for three to five sets and keep them on for two full nights including a lot of rehearsing and warming up. I like the sound of new strings and dislike breaking strings on stage so I change these strings after two long nights of playing. They sound great, feel great and stay in tune. I am glad I can get them in bulk from Juststrings.com